differentials

[scottac]

how often should the fluid in the differentials be drained and replaced. I don't see it anywhere in the owner's manual.

 

thanks in advance for all the replies

[Black02Silverado]

My manual just states to check and service as needed. I changed mine out just because I wanted to. I probably will change it back out at 100k. Just makes me feel better. That and the fact that it has a drain plug makes it easy to do. Heck the amount that it takes is minimal compaired to some things I spend cash on.

[ness5575]

I just changed out the fluid in my front and rear differentials at about 88k, and I was WAY over due. The stuff that I took out didnt look very good. I had never done it before and had I known how easy it was to do I would have never waited that long. From now on I will do it every 30k miles. For $20 and an hour of time it is worth it imo...

[JayMan]

Well, if you NEVER change the gear oil, you should make it through the warranty period

 

The owner's manual is vague, isn't it? My Canadian dealer, who really does seem to care, gave me the "Goodwrench Service Smart Guide Maintenance Schedule" supplement. They recommend gear oil changes at the first 5,000 km / 3,000 mi, then every 20,000 km / 12,000 mi!

 

Also, my Helm shop manual has the following in "General Information: Maintenance and Lubrication" Page 0-41:

 

"If your vehicle is used to pull a trailer, a rear axle fluid change is recommended after a break-in period. Change the rear axle fluid after the first 500 miles."

 

Hmmmm

 

High performance gear shops, like and Randy's Ring and Pinion, have GREAT advice on differential care. They recommend the initial service at 600 miles! That makes sense to me, since most of the wear particles are generated during break-in.

 

http://www.randysringandpinion.com/

 

When my 2000 GMC had 1,600 km / 1,000 mi on it, I changed everything: both axles, motor oil, ATF, and transfer case. I'm in it for the long haul!

 

Ness5575: If the oil looked that bad, better change it again soon just to flush everything out.